A reaction mixture containing CMP-Sialic Acid, an acceptor substrate, and CD73 is added to each well of a 96-well microplate.
The reaction is initiated by adding the sialyltransferase to each well of the microplate.
The Malachite Green Phosphate Detection Reagents are added to the wells. The reactions are terminated and a green color develops in proportion to the amount of inorganic phosphate released by the coupling phosphatase. The absorbance of the color at 620 nm is measured.